Manufacturing of sheet-iron



UNITED S 'PAiTENT OFFICE.

WILLIAM HIE SS, SR, OF READING, PENNSYLYANIA.

MANUFACTURING OF SHEET-l RON.-

specification forrning part of .Letters Patent No. 33,9I4t datd September 3, 1861.

To all whom it may cafncem:

Be it known that IQWILLIAM Rrnss, Sr., of Reading,'in the county o.,lBerks, in the State of Pennsylvania, have invented a new and useful Improvement in the Mode of M anufacturing Sheet-Iroinproducing an. article equal to the best Russia sheet-iron in luster and in its capability of resisting dampness or heat and of receiving acute bends without injury to its glossy surlace,aud which can be furnished for public use materially cheaper than the imported article, and which I have termed Adamantine Iron in 'orderLtodistinguish it from the Russian and every' kind of American sheet-iron, of which the following is a specification.

To enable others skilled in thezart to make and use my invention, will now proceed to describe m yim proved mode of manut'acturi'n g sheet-Iron in a full'and accurate manner.

I takebloom-iron platesand liave 'them rolled in the usual manner until their thickness is reduced to No. 22. -1 prepare in a vat of sufficient dimensions a mixture of equal parts, by weight, of chalk,porcelain-elay, and graphite ground upon an ordinary paint-mill and diluted with water to the consistencyof molasses. Into this mixture the still warm'plates are dipped, but. immediately withdrawn and put asideto dry. When dry theyiare packed eight to ten plates into a bundle and heated to a dark-red color in the usual manner for a continuation of the rolling process until reduced to the required thickness, and then tempered man an ealing-furnace. The'efl'ect produced by this mixture upon the plates is "as follows: This coating equalizes and retains theheat, secures the plates from scorching, protects the surface of the plates from the influence of atmospheric air, efl'ectually diminishing oxidation and the formation of scales, renders the plates 'free from cold-short, and consequently more tough when cold, and finally prepares them to yield,

qnickeneasier, and more completely the dross upon their surface by 'the process next to .be

described. l

, Next to the above rolling and tempering pro- .cess follows the cleaning of the plates and developing on thei surface a layer of pure iron. 1 For this operafon are required three strong wooden boxes, each large enough to receive a number of plates, stood up edgewise and without .comingin'to contact with each other. The

first of these boxes is filled with a bath consisting of one part concentrated sulphuric acid and three parts of water. In this bath the plates are placed edgewise and without coming into cont-actwit-h each other, and remain therein unt-il they appear entirely free from scales.

The second box contains a lye of one part potashdilutedwith twenty parts of water and fil-' tered. The plates are removed from the first box into this lye and placed in the same erect edgewise position, so as not to come into contact with each other, thereto remain'until the testing-strip indicates-that they have assumed a greenish-blue glossy. tint, when they are re--, moved into the third box, containing clear'run- .ning water,'fora thorough washin By the process above described the nature of the surface of theplates is greatly changed. The-bath in the first box dissolves the coating in anexceedingly shorttime. The application of sulphuric acid is preferable to muriatic orni- .-tricacid, becau'seit' generates no saltbycoming intocontact with the iron, and'jthus prevents a new oxidation on exposure to the, influence of atmospheric air. The lye in the second box neutralizes the acid and checks its further action upon the iron, absorbing the acid and developing upon the surface a layer of fine porous iron. .The running stream of pure water in the thirdbox removes all remaining im purities.

The plates, having been dried by the applica 7 tion of sawdust, are now'plaeed vertically and about twoinches apart into an oven, which must be heated withlight dry wood-Sutihas hemlock or white-pine -and provided with'a crown of fire-bricks over the furnace. separating the heating-chamber from the latter, and petforated with numerous small holes for dis-.

.tribntion from below. The fire is lighted after the oven has been charged with plates to its of the ovep are provided with suitable openings for the insertion of trying-strips. A careful examinationof these testing-strips w'ill'show the hluish'black glistening gradual productionof a, carbu'ret .on the surface, which at first appears scaly, and may be scraped off with aknife. Soon, however, this carburet will'be found to have embodied itself firmly with the iron and is no longer removable in the above manner.- From this period the-heat must be checked and the plates allowed gradually to cool. When the plates are removed from theoven their surface will be verysensitive to the action of a blowwitha polished hammer, or to the pressure between polished rolls, and it is to this polishing process to which the plates are next subjected.

1 The rolling, whenever found preferable,

should be done by means of highly-polished.

rollsof steel, such as are used for rolling out copper, silver, or sheet steel. The hammering is best accomplishedby means ofa first or Fore .haminer and a polishing-hammer, both of which should be light-say thirty or forty pounds-,andstriking rapid blows, both the hammer and anvil being highly polished.- The plate is worked under these hammers until its entire surface is evenly glazed and free from porous dull places, which operation is surprisngly expedited by the preceding treatmentof :he iron. The above cold rolling or hammerng will necessarily close the fibers of the iron llld make it harder and more elastic than dei'rable. It must therefore undergo the final vperation of tempering. .This is accomilishedin an oven similarinconstrnction to that lbOVG mentioned,it being,however,important 0. line the entire temperingwhamber with dates of firebricks. This chamber, upon being harged with plates at intervals of about one nch, is tightly closed to exclude atmospheric ir, whereupon the fire is kept up until the heat 1 the iron approaches the point at which it hanges from a black'to a dark-red color. This ven is, like the one above described, provided with openings for the insertion of trying-strips, s the progress of this tempering process reuires careful watching to prevent any overeating of the plates. The same will, upon reioval from this tempering-oven, be found to 1 ave lost very little of their previous smoothess and polish, while they have gained the :quired pliability, and are now ready for the iarket. subsequent passing of the plates,

however, between polished rolls, or a final treatment with a light hammer, will very much heighten the polish and produce a decided improvement in the appearance of theiron.

By a slight change in the treatment of the plates subsequent to the herein-described cleaning process a much lighter and more silverygray-colored surface may be obtained. For this end the'plates are, when dried, im-' mediately polished after their removal from the water, and afterwardtempere'd, like the bluish-black sheet-iron, with this difl'erence,

that at the beginning of thetempering process small qnantities of rosin'are injectedinto the chamber. This, by forming a heavier layer of condensed. smoke onfthe plates, much preserves their former color, besides producing a the following subdivisions:

'1. Themixtu're ofcqual parts, by weight, of chalk, porcelain -clay, and graphite diluted with water to the consistency of molasses, as described above vsubstantially in the manner and for the purpose specified.

The bath, consisting of one part concentrated sulphuric acid and three parts'water, substantially in the manner and for the pur-' pose specified.

3. The lye, consisting of one part potash diluted with twenty parts of water,snbstantially in the manner and for the purpose specified.-

, 4. The method of producing a carburet on the surface of the plates, and of embodying the said. cnrburet with the latter,substantially as and in the manner set forth in cation.

the speciti WILLIAM mass, sen. Witnesses:

FRANK. B. MILLER,

THOMAS MoRR1s. 

